It shrinkwraps everything in your current node_modules directory.

This includes platform specific dependencies that may not work on other platforms but now will cause npm install to fail instead of just printing a message about it.

So our current workflow has to be:

1. Update package.json 2. rm -rf node_modules/ 3. npm install --production # This doesn't include any of those pesky platform specific packages 4. npm shrinkwrap 5. npm install # Get the dev dependencies

As far as the other comments about npm, I just generally have more problems with it than rubygems/bundler and the general OS package managers.